1. Field of the Invention
This invention relates to high solids coating and/or impregnating compositions containing a film-forming component and a reactive diluent, curable at ambient conditions. Interest in the preservation of the environmental quality and in the conservation of energy, manifested by governmental implementation of increasingly stringent anti-pollution and energy conservation regulations, has generated considerable interest in the use of reactive diluents in coating compositions. These diluents are generally high boiling, low viscosity monomers that function as solvents during application but undergo cure of some kind, especially preferably under ambient conditions, and thereby become an integral part of the product coating. Pollution attributable to conventional solvent emissions is thereby reduced or eliminated and the necessity of a source of heat to evaporate solvent from the applied coating composition and to effect cure thereof is also thereby obviated.
2. Description of the Prior Art
Emmons, Nyi and Sperry, U.S. Pat. No. 4,071,489 issued Jan. 31, 1978 discloses air-drying coating compositions based on alkyd resins comprising at least one of dicyclopentenyl methacrylate or dicyclopentenyl acrylate, and a polyester or an alkyd resin having at least one unsaturated component curable by the addition thereto of a drier or a siccative, the composition optionally containing a volatile oxime stabilizer to prevent the oxidizing action of the drier when it is included in the composition prior to storage.
Emmons, Nyi and Sperry, U.S. Pat. No. 4,100,133 issued July 11, 1978 discloses autoxidizable compositions comprising at least one of dicyclopentenyl methacrylate or dicyclopentenyl acrylate, a copolymer containing at least one of dicyclopentenyl methacrylate and dicyclopentenyl acrylate, a siccative, and a volatile oxime stabilizer. The patent also discloses cured film products thereof.
Emmons, Nyi and Sperry, U.S. Pat. No. 4,138,390 issued Feb. 6, 1979 discloses autoxidizable compositions comprising at least one of dicyclopentenyl methacrylate and dicyclopentenyl acrylate, a film-forming polymeric binder, a drier, and a volatile oxime stabilizer. The patent also discloses air-dried film products thereof.
Emmons and Nyi, U.S. Pat. No. 4,097,677 issued June 2, 1978 discloses, as reactive non-volatile monomers, dicyclopentenyloxyalkyl methacrylate and dicyclopentenyloxyalkyl acrylate which are useful in the production of polymers, in coating and/impregnating compositions, and/or in molding, casting, or otherwise forming shaped articles.
Emmons and Nyi, U.S. Pat. No. 4,145,503 issued Mar. 20, 1979, and U.S. Ser. No. 908,427 filed May 22, 1978 now U.S. Pat. No. 4,261,872, which is a continuation-in-part of the application which issued as the aforementioned patent, disclose coating and/or impregnating compositions, curable by autoxidation, of at least one of dicyclopentenyloxyalkyl methacrylate or dicyclopentenyloxyalkyl acrylate, a drying oil or a film-forming addition or condensation polymer, a siccative, and, optionally, a volatile oxime stabilizer.
Barrett and Strain, U.S. Pat. No. 2,160,532 issued May 30, 1939, disclose the preparation of monomeric mixed esters of polyhydric alcohols such as diols, glycols, and the like with monocarboxylic acids, at least one of which is an alpha, beta-unsaturated acid, for example methacrylic acid, the other acids being fatty acids. Specifically disclosed are soybean oil diglyceride monomethacrylate, soybean oil monoglyceride dimethacrylate, glycol laurate methacrylate and related materials. These are used in coatings with peroxide initiators or metal salt driers or with other resins.
D'Alelio, U.S. Pat. No. 3,284,385 issued Nov. 8, 1966, discloses a preparation and an anionic polymerization of methacryloxyethyl and acryloxyethyl esters of drying oil fatty acids, for example linseed oil fatty acid, obtained by direct esterification or transesterification of the corresponding fatty acid monoethoxylates.
Harrison, U.S. Pat. No. 2,593,444 issued Apr. 22, 1952 discloses acrylate and methacrylate esters of unsaturated alcohols derived by the reduction of drying oil and semi-drying oil fatty acids.
In the related, co-pending application U.S. Ser. No. 014,676 filed Feb. 23, 1979 and now U.S. Pat. No. 4,255,196, by Emmons, Sperry, and Kaplan, there are disclosed ink compositions containing drying oil fatty acid esters of addition polymerizable ethylenically unsaturated hydroxyl-containing compounds, especially acryloxyalkyl and methacryloxyalkyl esters of drying oil fatty acids.
Although the use of the dicyclopentenyloxyalkyl methacrylates and the methacryloxyalkyl and acryloxyalkyl esters of drying oil fatty acids would present improvements in the class of reactive diluent monomers, further improvement is desired. In some applications, especially those conducted at ambient temperature, i.e. 0.degree.-100.degree. F., dicyclopentenyloxyalkyl methacrylate, for example dicyclopentenyloxyethyl methacrylate, and compositions based thereon cure more slowly than is desirable. This slow cure rate is believed to be caused, in part, by oxygen inhibition of homopolymerization, a phenomenon well established with methacrylate monomers as reported by F. R. Mayo and A. A. Miller, J. Am. Chem. Soc., 80, 2493 (1958). While oxygen is needed by the methacrylate monomer to form the hydroperoxide requisite for homopolymerization, excessively high oxygen concentration results in the slow formation of a copolymer containing alternating units of oxygen and the methacrylate monomer rather than in rapid homopolymerization of the methacrylate monomer. In order to overcome the slow cure rate of methacrylate monomer-containing systems, it is often necessary to add polymerization accelerators such as peroxides or hydroperoxides to compositions containing monomers such as dicyclopentenyloxyalkyl methacrylate. This, however, generally diminishes the storage stability of such systems.
A problem frequently encountered with the use of methacryloxyalkyl and acryloxyalkyl esters of drying oil fatty acids is that polymers of these monomers are more soft and extensible than is desirable.